Are There Any Non-Carnivorous Plants?

There may be more meat-eating plants out there than we previously thought: It’s all about defining your terms.

Murderous plants: Victorian Gothic, Darwin and modern insights into vegetable carnivory,” Mark W. Chase, Maarten J. M. Christenhusz, Dawn Sanders, Michael F. Fay, Botanical Journal of the Linnean Society, 161 (4), December 2009, pp. 329-356. DOI: 10.1111/j.1095-8339.2009.01014.x. The authors from The Jodrell Laboratory and the Botany Department of the Natural History Museum in London collaborated to produce this update on the state of carnivory in the Plant Kingdom. They write:

“Darwin’s interest in carnivorous plants was in keeping with the Victorian fascination with Gothic horrors, and his experiments on them were many and varied, ranging from what appears to be idle curiosity (e.g. what will happen if I place a human hair on a Drosera leaf?) to detailed investigations of mechanisms. Mechanisms for capture and digestion of prey vary greatly among the six (or more) lineages of flowering plants that have well-developed carnivory, and some are much more active than others. Passive carnivory is common in some groups, and one, Roridula (Roridulaceae) from southern Africa, is so passively carnivorous that it requires the presence of an insect intermediate to derive any benefit from prey trapped on its leaves. Other groups not generally considered to be carnivores, such as Stylidium (Stylidiaceae), some species of Potentilla (Rosaceae), Proboscidea (Martyniaceae) and Geranium (Geraniaceae), that have been demonstrated to both produce digestive enzymes on their epidermal surfaces and be capable of absorbing the products, are putatively just as ‘carnivorous’ as Roridula. There is no clear way to discriminate between cases of passive and active carnivory and between non-carnivorous and carnivorous plants – all intermediates exist. Here, we document the various angiosperm clades in which carnivory has evolved and the degree to which these plants have become ‘complete carnivores’. We also discuss the problems with definition of the terms used to describe carnivorous plants.”

Thanks to Hugh Henry for bringing this to our attention.